[SOLVED] Waveshare 5.5 AMOLED HDMI Display - screen rotate

[dewen]

You can edit the ~/.xinitrc and add the xrandr command there.
Have you tried in the peripheral config to set the display as HDMI and rotated ?

   

As you taught me, there is already an xrandr command in ~/.xinitrc. 
I changed 'left' to 'right,' and it works! Thank you!